ИСТИНА

The fabrication regimes and properties of microgel/enzyme thin films were examined. The films were formed at conductive substrates (graphite, gold) via two-steps, sequential adsorption of a both temperature- and pH-sensitive microgel poly(N-isopropylacrylamide-co-3-(N,N-dimethylamino)propylmethacrylamide) (poly(NIPAM-co-DMAPMA), followed by enzyme (tyrosinase, choline oxidase and/or butyrylcholinesterase) adsorption under different pH and temperature conditions. By temperature-induced stimulating both (i) poly(NIPAM-co-DMAPMA) microgel adsorption at T>VPTT (volume phase transition temperature) and (ii) following sponge-like enzyme loading at T<VPTT, an increased enzyme loading was achieved, thereby resulting in increased biosensor sensitivities. Since sponge-like approach to enzyme adsorption was found to be dependent on the molecular weight (globule size) of the enzyme, the bienzymatic system with spatially separated enzymes was prepared in one-step as demonstrated for the system with co-immobilized choline oxidase/butyrylcholinesterase.